With a growing human population, cities keep growing worldwide altering ecosystem and thereby affecting the species living in these areas. Most studies of urbanization and its effect on ecosystem have been conducted in the western world and little is known about its effect in the neotropical part of the world. I examined effects of fragment size, vegetation structure and connectivity of urban green areas on bird species richness, mean abundance, diversity and biomass in La Paz, Bolivia. Additionally, the effects of different disturbance variables on bird community were evaluated. In total, 36 bird species were found in 24 fragment of varying size, connectivity and level of disturbance. Bird species richness decreased with increasing disturbance while connectivity and fragment size did not contribute significantly to explain the variation in species richness at count point scale (p>0.005, multiple linear regression). At fragment scale, however, species richness increased with fragment sizes, which has been shown in other studies from neotrophical regions. Variation in abundance, diversity or biomass could not be explained by connectivity, fragment size or disturbance. Furthermore, coverage of construction had a negative effect on species richness while coverage of bushes and coverage of herbs were negatively related to biomass and diversity, respectively. The composition of bird species differed with size and disturbance of the fragments, so that more omnivorous and granivorous species such as Zonotrichia capensis, Turdus chiguanco and Zenaida auriculata, were present in areas highly affected by human activities. Larger fragments, less affected by human presence held a larger proportion of insectivorous species.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:liu-79408 |
| Date | January 2012 |
| Creators | Hiding, Camilla |
| Publisher | Linköpings universitet, Institutionen för fysik, kemi och biologi, Linköpings universitet, Tekniska högskolan |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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